key technology issues for ieee802.11ac next gen. wlanc1... · etri etri 인터넷연구부문...

ETRIETRI 인터넷연구부문무선통신연구부

정 민 호

2010.06.28. KRnet 강연

Key Technology Issues for IEEE802.11ac Next Gen. WLAN

ETRI

IT R&D Global Leader

ETRI

Contents

4. IEEE 802.11 VHT 기술이슈 (11ac/11ad)

3. IEEE 802.11 VHT 표준동향 (11ac/11ad)

2. 기존 802.11a/b/g/n과 VHT의출현배경

1. IEEE 802및 802.11 Overview

5. IEEE 802.11ac D1.0 요약

ETRI


ETRI

Sensor (LR-PAN)IEEE 802.15.4(Zigbee Alliance)

IEEE 802.15.4f(AutoID Center)

IEEE 802 개요

IEEE 802.15.3 UWB

Wi-Media, MBOA

WAN

MAN

LAN

PAN ETSI HiperPAN

IEEE 802.11 Wi-Fi Alliance

ETSI-BRAN HiperLAN2

IEEE 802.16d WiMAX

ETSI HiperMAN & HIPERACCESS

IEEE 802.20IEEE802.16e

3GPP (GPRS/UMTS)3GPP2 (1X--/CDMA2000)

GSMA, OMA

RANIEEE 802.22

WAN: Wide Area NetworkRAN: Regional Area NetworkOMA: Open Mobile Alliance

ETRI


ETRI

IEEE 802.11 WLAN 개요

WLANIEEE 802.11

WLANIEEE 802.11

TGwProtected management

frames

TGwProtected management

frames

TGaWLAN 5GHz OFDM

TGaWLAN 5GHz OFDM

TGbWLAN 2.4GHz CCK

TGbWLAN 2.4GHz CCK

TGeProtocol for QoS

TGeProtocol for QoS

TGgWLAN 2.4GHz OFDM

TGgWLAN 2.4GHz OFDM

TGzDirect link setup

TGzDirect link setup

TGaaVideo transport streams

TGaaVideo transport streams

TGacVery high throughput at <6GHz

TGacVery high throughput at <6GHz

TGmbAccumulated maintenance

TGmbAccumulated maintenance

TGnHigh throughput

TGnHigh throughput

TGpVehicular environment

TGpVehicular environment

TGv Network management

TGv Network management

TGsMesh networking

TGsMesh networking

TGuInterworking with external

TGuInterworking with external

TGadVery high throughput at 60GHz

TGadVery high throughput at 60GHz

TGhDynamic frequency selection

TGhDynamic frequency selection

TGiSecurity system

TGiSecurity system

TGf/rFast handover

TGf/rFast handover

Orange : recent hot issueBlue : on activityGreen : terminated

TGafTV White Space

TGafTV White Space

S1GSmart GridS1G

Smart Grid

ETRI기존 주요WLAN 규격

기존 WLAN 규격 (802.11a/b/g/n)

텍스트

IEEE 802.11h : Dynamic Frequency Selection IEEE 802.11i : 차세대보안시스템 IEEE 802.11f/r : Fast Handover (with IEEE 802.21 : MIH) IEEE 802.11s : Mesh Networking Wi-Fi 인증용기능 (2007.03부터시작됨)

사용주파수 대역 2.4GHz 5GHz 비고

무선전송

규격

11b o x 11Mbps (CCK)

11g o x 54Mbps (OFDM)

11a x o 54Mbps (OFDM)

11n o o 130~600Mbps (MIMO-OFDM)

11p x 5.850~5.925 27Mbps (11a 기반 텔리매틱스)

11e o o QoS 지원 MAC 프로토콜

ETRI

802.11n WLAN 규격

IEEE 802.11 TGn Spec. since 2003.11

Requirements 11a(5GHz) 및 11b/g(2.4GHz)와의호환성지원 주파수효율 3bps/Hz 이상, MAC속도 100Mbps 이상

주파수 대역: 2.4/5GHz 대역최대전송속도

130Mbps @ 2stream / 20MHz BW(mandatory) 600Mbps @ 4stream / 40MHz BW (optional)

주요 기술적 특성 MIMO-OFDM 방식을처음도입함

ETRI

802.11n WLAN 규격 (2)

802.11n 주요 특성Feature Mandatory Optional

Number of spatial stream 1 and 2 3 and 4

Number of transmit antenna 2 Greater than 2

bandwidth 20MHz 40MHz

Number of occupied subcarriers 56 in 20MHz 114 in 40MHz

Number of data subcarriers 52 108

Number of pilot subcarriers 4 6

Modulation order BPSK, QPSK, 16-QAM,

64-QAM

256-QAM for

Beamforming mode

Code rate 1/2, 2/3, 3/4, 5/6

Guard interval 800ns 400ns

Channel coding Convolutional code LDPC

기타사항 Tx beamforming

ETRI

802.11n WLAN 규격 (3)

802.11n 표준 일정Event Name Accepted Dates

Actual PredictedPAR Approved Sep ‘03Initial WG Letter Ballot Mar ‘06Recirculation WG Letter Ballot Oct ‘07Form Sponsor Ballot Pool Jul ‘08Initial Sponsor Ballot Nov ‘08Recirculation Sponsor Ballot Jan ‘09Final WG Approval Jul ‘09Final EC Approval Jul ‘09RevCom/ Stds Board Approval Sep ‘09Publication Oct ‘09 Nov ‘09

ETRI

VHT 출현배경

VHT (Very High Throughput) 802.11n 성능포화여건

2008년을기점으로 802.11n상용모뎀의확산 수요급증하는초고화질영상전송지원불가능

• Lightly(or not)-compressed video 전송: 1~3Gbps

기존WLAN에서의성능조건변천내역을참조하여, VHT 요구조건을설정하고자하는내부움직임

• 11b => 11a => 11n 과정에서 5배수상향설정방식이효과적이었음

2007년 5월 VHT Study Group을결성하여논의착수

ETRI

VHT 출현배경 (2)

VHT의 출현에 따른 예상 신규수요 초고속근거리인터넷생태계모델의재정립

전송장치초고속화로융합용디바이스수요신규창출

Need for 802.11 VHT standard

Maintain Wired equivalence

• GigE is widely deployed• 10GigE is emerging

Faster CPUsLarger and Faster StorageHD content

• SSD Growing 2x a year• >80 GB iPOD and camcorders• DVD Capacity growing 8x• Blue Ray– 50 GB dual layer

Competitive environment driving Proprietary 11n extensions

Proprietary modes fragment the market

Higher Capacity

Gigabit nano-cells free capacity for normal network use

ETRI

VHT 진행상황

VHT Study Group 진행 VHT 성능요구논의사항 (2007.05~)

• 11n대비전송속도및주파수효율의 5배이상향상• Coverage의증대 (11n 시엔옥내외 60~70m)• Backward compatibility 지원• IMT-Adv Nomadic 모드에대해서는독립적관계• 전력소모량감소기대 (11n 대비보다효율적구현)

VHT 논의의 2갈래진화 (2007.11~)• 신규시장예측수요(11n대비 5배이상속도) 충족을위해서안테나및

BW 자원의동반확장필수적• 기존WLAN밴드의포화및WPAN밴드(60GHz)기술진화를감안하여 2가지별도 VHT 진행

– VHTL6 (기존 11n에서쓰던 5GHz 대역사용 VHT)– VHT60 (기존 PAN에서쓰던 60GHz 대역사용 VHT)

ETRI

VHT 진행상황 (2)

VHTL6 Task Group 출범 VHTL6 (5GHz band VHT)

• 2008년 11월 (Dallas 회의) Task Group (IEEE802.11ac) 본격출범• Task Group Document 작업완료

– Functional Requirements, Channel Model, Framework, Selection Procedure

• 2009년 11월부터 Ad-hoc Group 기술논의본격착수– PHY, MAC, MU-MIMO, COEX의 4개의 Ad-hoc Group 중심기술논의

• 2011년 6월현재 IEEE802.11ac D1.0 승인상태임• IEEE802.11ac의기술적인주요특징

– 80MHz BW 채택이아예불가능한 2.4GHz 밴드는서비스제외– 5GHz 밴드에서 80/40MHz BW 활용방안연구– 주파수효율의향상기술집중연구

ETRI


VHT60 Task Group 출범 VHT60 (60GHz band VHT)

• 2009년 1월 (LA회의) Task Group (IEEE802.11ad) 본격출범• Task Group Document 작업완료

– Functional Requirements, Channel Model, Framework, Selection Procedure

• WiGi Alliance를중심으로집중적인기술논의를진행함. • 2011년 6월현재, IEEE802.11ad Letter Ballot 진행중임• IEEE802.11ad의기술적인주요특징

– 60GHz밴드에서 2~6 GHz BW 사용하는 RF 기술이핵심적– WPAN(802.15.3c)와의차별성입증및 Coverage 확대기술에주력– 기존WLAN(11a/b/n)과의호환성지원을위한 multi-radio가필요함

ETRI


Technical Ad-hoc Groups in IEEE802.11ac 각 Adhoc Group 별주요논의주제

한국전자통신연구원

IEEE802.11ac

Coex PHY MAC MU- MIMO

• Pilots• Data tones• Preamble• Enhanced MCS• Sounding• Higher Bandwidth

modulation• Parsing and Interleaving• Coding, STBC• Spatial Mapping & Cyclic

Delays

• OBSS Management• Multi-Channel

• Non-contiguous channelization

• MC MAC protocol• > 80MHz channel

• Backwards compatibility • CCA• Channel access Fairness• Scanning and channel

selection

• Downlink MU-MIMO • Uplink MU-MIMO• MU-MIMO parameters

(e.g. # of streams, # of clients)

• Training protocols• ACK protocols • Reservation/polling

• Power saving• Capability negotiations• Frame formats

ETRI

VHT Usage Model

VHT Usage Model• 각 Task Group에서논의를착수한상태임• WFA(Wi-Fi Aliance)의해당문서로부터논의착수• 사용환경母집단에대하여 VHTL6, VHT60 Mapping이루어짐

VHTL6 Candidate Required throughput

• Lightly compressed video• Compressed video

Environment• In room or on desk, short

range• larger area, longer range• Dynamically changing• LOS/NLOS

VHT60 Candidate Required throughput

• Uncompressed video• Lightly compressed video• Compressed video

Environment• In room or on desk, short

range• Fixed point-to-point• Mostly LOS

ETRI

802.11ac Specific Usage

Category # Usage model Band802.11ac 802.11ad

1. Wireless Display 1a Desktop Storage & Display x1b Projection to TV or projector in conf room (lightly compressed video) x x

1c In room gaming (lightly compressed video) x x1d Streaming from camcorder to display (lightly compressed video) x x

1e Broadcast TV field pick up ?1f Medical imaging surgical procedure support x

2. Distribution of HDTV 2a Lightly compressed video streaming around the home x2b Compressed video streaming around home x2c Intra large vehicle (e.g. airplane) applications x x2d Wireless networking for small office x x2e Remote medical assistance ½ ½

3. Rapid upload/download 3a Rapid sync-n-go file transfer x x3b Picture by picture viewing x3c Airplane docking x3d Movie content download to car x3e Police / surveillance car upload x

4. backhaul 4a Multi-media mesh backhaul x4b Point-to-point backhaul x x

5. Outdoor campus / auditorium 5a Video demos / tele-presence in auditorium ?5b Public safety mesh x

6. Manufacturing floor 6a Manufacturing floor automation x

VHT 사용환경 Mapping Table 일람

ETRI

802.11ac Key Features

Overview with mandatory/optional features Bandwidth modes:

• 20 MHz, 40 MHz, 80 MHz – mandatory• 160 MHz (i.e. contiguous 160 MHz) -- optional• 80+80 MHz (i.e. non-contiguous 160 MHz) -- optional

MCS• MCS 0~7 : same as 802.11n, mandatory (from BPSK ½ to 64QAM 5/6)• MCS 8, 9 : 256-QAM ¾, 256-QAM 5/6 – optional

Single, unified frame format for both SU and MU Transmission parameters list

ETRI

802.11ac Key Features (2)

VHT PHY Key Features

ETRI


Timing related parameters

ETRI


Examples of MCSs

ETRI


Channelization

Transmission of PPDU with BW less than the basic service set (BSS) BW

ETRI


PPDU format comparison

Auto-detection• 802.11n : detect Legacy/HT using HT-SIG

– HT-SIG : Q-BPSK

• 802.11ac : detect Legacy/HT/VHT using VHT-SIG-A– VHT-SIG-A1 : BPSK– VHT-SIG-A2 : Q-BP나

All the VHT PPDH fields since VHT-STF are beam-formed• For single-user/multi-user beam-forming

한국전자통신연구원

ETRI

802.11ac Technical Issues

Optimal BW Expansion 주파수대역폭을최적확장하여데이터용량과전송속도를증가

VHTL6의 BW 활용방안• Legacy mode (11a/n): 20/40MHz 지원• VHTL6 : 40/80/160 MHz지원• Preamble 및주파수할당방법의효율적인재설계

128 subcarrier

40MHz

128 subcarrier 128 subcarrier

80MHz

ETRI

802.11ac Technical Issues (2)

SDMA (Multi-User MIMO for WLAN)• SDMA allows simultaneous

transmission to multiple users.– 11n allows transmission to

one user at a time.• SDMA has the following

advantages:– Increase network throughput

by adding antennas at the AP– Reduce client antenna

requirements for low cost clients.

– Increase per-client throughput by adding antennas at client (MIMO) and/or higher BW

• In 802.11ac, only DL(downlink) MU-MIMO is allowed (not UL MU-MIMO).

ETRI


Explicit & “Compressed V” BF For single user and multi-user as well Only agreed mode to support beamforming for 802.11ac Transmission of a set of angle information of V matrix using “Givens

rotation” angles (φ’s) and “Realization” angles (ψ’s)• SU-MIMO : Qk = Vk

• MU-MIMO : Qk can be calculated by using and perhaps combining Vk

and SNRs from Bfees to suppress crosstalk between participating BFees

FB angles for 4 TX antennas (e.g.)

ETRI


Explicit & “Compressed V” BF (2) Average SNR of stream i of matrix V

• Averaged SNR for stream i

Delta SNR is additionally required for 802.11ac MU-MIMO BF• Delta SNR is deviation in dB of per-tone SNR relative to average SNR

Tone grouping/interpolation and BF segmentation are used VHT Sounding protocol using NDP (Null Data Packet)

ETRI


Contiguous/Non-Contiguous 160 MHz• Contiguous 160 MHz

Transmitted signal consists of a single contiguous frequency spectrum with 160 MHz bandwidth

• Non-contiguous 160 MHz Transmitted signal consists of two frequency segments,

each 80 MHz wide Limit to two non-contiguous segments for reasonable

tradeoff between complexity and flexibility

U-NII Worldwide U-NII 3U-NII 2U-NII 1WLAN - 160 MHz

80 MHzU-NII Worldwide U-NII 3

WLANRadar

U-NII 2U-NII 1WLANWLAN 80 MHz

Radar

WLAN - 160 MHz

ETRI


Dynamic Bandwidth Operation Dynamic BW: 20/40/80 MHz

• If 80 MHz is free, transmit using 80 MHz, else• If 40 MHz (including primary) is free, transmit using 40 MHz, else• If the secondary channel is not free, data is transmitted over the primary

channel. Static BW: 0/80MHz

• If at least one of the secondary channels is busy, the transmitter restarts the backoff procedure over the primary channel without incrementing the retry counter.

Bandwidth & Static/Dynamic indications are needed in non-HT PPDUs• Those information is indicated at scrambler seed in every corresponding PPDU.

ETRI


Dynamic Bandwidth Operation (2) Both initiator and responder are capable of dynamic BW

operation• RTS is transmitted on channels that are sensed free at the initiator • CTS response is only sent on channels that are occupied by the

RTS and are determined to be free at the responder (a valid PHY mode is used, meaning only 20/40/80/80+80/160MHz transmissions allowed)

• RTS/CTS frames carry the available bandwidth information• Initiator transmits data only over channels indicated free by CTS

response

ETRI


CCA (Clear Channel Assessment) As in 11n, the main mechanism for coexistence with non-802.11

devices is clear channel assessment (CCA). Similarly stringent to any signals (non-OFDM) for primary 20MHz

channel, secondary 20/40/80 MHz channels (energy detection with -62 ~ -56 dBm)

Similarly stringent to WLAN signals for primary 20/40 MHz channels (preamble detection with a threshold of -82 ~ -79 dBm)

CCA level table is expanded to cover 80/160MHz usage More stringent to NON_HT, HT_MF, HT_GF or VHT format signals for

secondary 20/40 MHz channel (with the threshold of -72~ -69 dBm, compared to -62 ~ -59 dBm level in 802.11n)

More stringent secondary CCA level is suggested in 802.11ac to reduce overlapping BSS effect due to wider bandwidth usage.

ETRI

802.11ac 표준화 향후 일정한국전자통신연구원

향후 표준화 일정

표준화 추진체계

Jan Mar May July Sept Nov Jan Mar May July Sept Nov Jan Mar May July Sept Nov

2011 2012 2013

D1.0 WG LB starts

D2.0 Recirc D3.0 Recirc D4.0 Recirc

D5.0Sponsor Ballt Starts

D6.0 Recirc D7.0 Recirc

Form Sponsor ballot pool

ACcelerate

TGac사전 논의 및기고문 제출

기술 제안

사전 논의 및기고문 제출

피드백 (ETRI, Qualcomm, LG)

기술 제안

국내전략발굴수립

국내규격제정준비

ETRI

802.11ad Specific Usage

Usage modes ranking orderingRankordering Based on Anticipated Market Volume

1c In room Gaming3a Rapid Sync-n-Go file transfer1b Projection to TV or Projector in Conf Rom2a Lightly compressed video streaming around home2b Compressed video streaming in a room or to home1d Streaming from Camcorder to Display3b Picture by Picture viewing1a Desktop Storage & Display2d Wireless Networking for Small Office6a Manufacturing floor automation3d Video Content Download to car4a Multi-Media Mesh Backhaul4b Point-to Point Backhaul3e Police / Surveillance Car Upload1f Medical Imaging Surgical Procedure Support2c Intra Large Vehicle (e.g. airplane) Applications5b Public Safety Mesh1e Broadcast TV Field Pick Up5a Video demos / telepresence in Auditorium2e Remote medical assistance3c Airplane docking

Rankordering Expected Marketing Timing

2b Compressed video streaming in a room or t.o. home2a Lightly compressed video streaming around home3e Police / Surveillance Car Upload1c In room Gaming1b Projection to TV or Projector in Conf Rom3b Picture by Picture viewing1a Desktop Storage & Display2d Wireless Networking for Small Office6a Manufacturing floor automation1d Streaming from Camcorder to Display3a Rapid Sync-n-Go file transfer4a Multi-Media Mesh Backhaul4b Point-to Point Backhaul1f Medical Imaging Surgical Procedure Support3d Video Content Download to car3c Airplane docking2e Remote medical assistance5b Public Safety Mesh2c Intra Large Vehicle (e.g. airplane) Applications1e Broadcast TV Field Pick Up5a Video demos / telepresence in Auditorium

ETRI

802.11ad Technical Issues

Fast session transfer Provides a seamless transfer of an active session from the 60 GHz

band to the 2.4/5GHz band, and vice versa Allows devices to maintain connectivity under dynamic conditions

• The devices use very high throughput 60 GHz link(s) when the 60 GHz links are operational and retain the extended range and reliability afforded by the 2.4 or 5 GHz band when the 60 GHz links are not operational

<6GHz transmission range

60GHz directional transmission

ETRI

802.11ad Technical Issues (2)

Coexistence TGad is required to create a Coexistence Assurance

document demonstrating coexistence with other systems in the band in a shared 60 GHz band in home and enterprise environments.

Liaison with 802.15.3c (mmWave Alternative PHY) Liaison with 802.19 (Coexistence Technical Advisory

Group)

ETRI

802.11ad Technical Issues (3)

60GHz CMOS transceiver design New designs using standard chip processes offer

enormous cost reduction vs. traditional high frequency designs

X Digital CMOScan now support

60 GHz

ETRI

802.11ad 표준화 향후 일정

Official timeline schedule 2008.12 : PAR approved 2010.09 : D1.0 & WG Letter Ballot Starts 2011.03 : D2.0 2011.05 : D3.0 (current status) 2011.09 : Form Sponsor Ballot Pool 2011.12 : Sponsor Ballot Starts 2012.03 : Sponsor Ballot Recirculation 2012.07 : Final WG approval 2012.07 : Final EC(Executive Committee) approval 2012.12 : RevCom(Review Committee) & Standards

Board approval

ETRI

802.11ad 표준화 향후 일정 (2)

ETRI

Appendix

IEEE802.11ac Draft 1.0 Summary Approved in May 2011

ETRI

Frame Formats

New control frames Added NDPA and Sounding Poll (section 6.3.3.2 and 6.3.3.3 of Spec

Framework) Management frames

New management IEs• VHT Capabilities element (section 6.2 of Spec Framework)• VHT Operation element (section 6.2 of Spec Framework)• VHT BSS Load element (section 6.3.2.2 of Spec framework)

New action frames (VHT category added)• VHT Compressed Beamforming frame (section 6.3.6.1 of Spec Framework)• Group ID management frame• Notify Operating Mode frame (section 6.3.6.2 of Spec Framework)

A-MPDU Extended length field to 14 bits Addition of EOF bit (from section 6.3.7.1 of Spec Framework)

Slide 39

ETRI

Frame Formats

VHT Capabilities element VHT BSS always includes the HT Capabilities element Therefore, VHT Capabilities element only includes

• Capabilities not present in HT Capabilities element or• Capabilities directly applicable to VHT PPDU

VHT Operation element VHT BSS always has HT Operation element Therefore, VHT Operation element only includes

• Channel width• Center frequency for 2 segments (to support non-contiguous)• Primary channel is specified in HT Operation element

Slide 40

ETRI

Frame Formats

VHT Compressed Beamforming Frame From section 6.3.6.1 of Spec Framework

(and based on Compressed Beamforming frame (11n)) Contains the following fields:

• VHT MIMO Control field– Based on 11n MIMO Control field

• VHT Compressed Beamforming Report field– Based on 11n Compressed Beamforming Report field

• MU Exclusive Beamforming Report field– New field for MU-MIMO (and only included with MU sounding)– Additional per tone SNR information

Slide 41

ETRI

MAC Sub-layer Functions

RTS/CTS in wider channels(section 6.9 of Spec Framework)

9.2 DCF9.6 Multi-rate support

These sections are updated to describe• BW signaling using RTS/CTS frames in non-HT duplicate format• Rules for CTS response based on received RTS and secondary channel

CCA• Rules for Data transmission based on receive CTS

Slide 42

ETRI


9.7d A-MPDU operation9.7d.5 Transport of A-MPDU by the PHY data service

Updated to require A-MPDU in VHT format frame9.7d.6 A-MPDU padding for VHT format PPDU

New section describing A-MPDU padding of VHT PPDUs9.7d.7 Transport of VHT single MPDUs

From section 6.5 of Spec Framework Rules for transporting a single MPDU in a VHT frame

9.7d.8 Partial AID in VHT PPDUs From section 6.6 of Spec framework Rules for setting Partial AID field in VHT PPDUs

Slide 43

ETRI


TXOP Sharing(From section 6.4 of Spec Framework)

3 Definitions Definitions for Primary AC, etc. (from Spec Framework)

9.9 HCF9.9.1.2 EDCA TXOPs9.9.1.2a Sharing an EDCA TXOP9.2.1.4 Multiple frame transmission in an EDCA TXOP

Updated to describe TXOP sharing concept

Slide 44

ETRI


Backoff procedure(From section 5.2 of Spec Framework)

9.9.1.2 EDCA backoff procedure Updated to describe backoff operation with MU-MIMO frames

Slide 45

ETRI


Sounding protocol(From section 6.7 of Spec Framework)

9.21 Null data packet (NDP) sounding9.21.5 VHT sounding protocol

Sounding and feedback protocol rules

Slide 46

ETRI

Layer Management

10.4.7 PLME-TXTIME.confirm The MAC needs to know how much padding is to add to the A-MPDU MAC sends PLME-TXTIME.request to PHY with LENGTH of useful

data, MCS, etc. for each user PHY returns PLME-TXTIME.comfirm primitive with

• TXTIME (original purpose)• PSDU_LENGTH[]

– Number of octets in PSDU including padding– Returned as an array since it is per user

Keeps the formula for determining number of octets in PSDU in one place in the spec

22.4.3 TXTIME and PSDU_LENGTH calculation PHY section where TXTIME and PSDU_LENGTH calculation is

described

Slide 47

ETRI

MLME

DL MU-MIMO Power Save(from section 6.1.1 of Spec Framework)

11.2 Power management11.2.1 Power management in infrastructure network11.2.1.4a Power management during MU-MIMO

transmissions11.2.1.4b VHT STA power management modes New sections to describe power save during MU

TXOPs

Slide 48

ETRI

MLME

Rules for AID assignment(from section 6.6 of Spec Framework)

11.20 VHT BSS operation11.20.1 AID assignment by VHT AP Rules to prevent AID assignment that results in two

STAs having the same Partial AID

Slide 49

ETRI

MLME

11.20 VHT BSS operation11.20.3 Basic VHT BSS functionality

Rules for transmitting PPDU of various BW:• All transmission must include primary channel• All transmission must use valid 20/40/80/160/80+80 MHz channel

11.20.4 STA CCA sensing in VHT BSS(from section 5 of Spec Framework)

To transmit 40 MHz PPDU, secondary channel must be idle PIFS before transmission To transmit 80 MHz PPDU, secondary channel and secondary 40 MHz channel must be idle

PIFS before transmission To transmit 160/80+80 MHz PPDU, secondary 20 MHz channel, secondary 40 MHz channel,

secondary 80 MHz channel must be idle PIFS for transmission

Slide 50

ETRI

PHY service specification

12.3.5.10 PHY-CCA.indication Extending primitive to 80 MHz, 160 MHz and 80+80

MHz channels

Slide 51

ETRI

OFDM PHY

BW signaling use scrambler init in SERVICE field(from section 3a in Spec Framework)

17.2.2 TXVECTOR parameters17.2.3 RXVECTOR parametersEtc.

Parameters are added for INDICATED_DYN_BANDWIDTH,INDICATED_CH_BANDWIDTH

17.3.5.4 PLCP DATA scrambler and descrambler Details on generating scrambler init field to signal

• Dynamic/Static• BW indication

Slide 52

ETRI

VHT PHY

Clause 22 maps directly from section 3 of Spec Framework

22.1 Introduction Overview with mandatory and optional feature list Bandwidth modes:

20 MHz, 40 MHz, 80 MHz – mandatory 160 MHz (i.e. contiguous 160 MHz) -- optional 80+80 MHz (i.e. non-contiguous 160 MHz) -- optional

MCS 0-7 – same as 802.11n, support mandatory 8 and 9 – 256-QAM ¾, 256-QAM 5/6 – optional

Single, unified frame format for both SU and MU

Slide 53

ETRI

VHT PHY

22.2 VHT PHY service interface VHT PHY includes HT PHY and OFDM PHY FORMAT parameter

Non-HT (i.e. OFDM PHY), HT_MF, HT_GF and VHT CH_BANDWIDTH parameter

HT_CBW20, HT_CBW40, HT_CBW80, HT_CBW160, HT_CBW80+80 NON_HT_CBW20, NON_HT_CBW40, NON_HT_CBW80,

NON_HT_CBW160, NON_HT_CBW80+80 (HT/NON_HT reference in CBW is redundant since captured in

FORMAT, we did not change this, but expect to in future revisions)

Slide 54

ETRI

VHT PHY

22.2 VHT PHY service interface (continued) MU parameters

GROUP_ID (value to place in Group ID field) NUM_USERS Array of parameters with NUM_USERS entries

• USER_INDEX (integer 0-3, user position in Nsts array)• MCS• NUM_STS• LENGTH (value in VHT-SIG-B)• PSDU_LENGTH (actual PSDU length)

SU parameters Same as per user list above, but with NUM_USERS set to 1 PARTIAL_AID

Slide 55

ETRI

VHT PHY

22.3 VHT PLCP sub-layer22.3.2 VHT PPDU format

Spec Framework Figure 3 converted to text plus diagram22.3.3 Transmitter block diagram

Functional blocks for creating various parts of PPDU22.3.4 Overview of the PPDU encoding process22.3.5 Modulation and coding scheme

References to section 22.6 (tables detailing rate-dependent parameters)22.3.6 Timing-related parameters

List of timing and other frequently used parameters22.3.7 Mathematical description of signals

Mathematical description of the transmitted signal22.3.8 Transmission of PPDU with less than BSS bandwidth

Adjustments to center frequency to derive narrow bandwidth signals

Slide 56

ETRI

VHT PHY

22.3 VHT PLCP sub-layer (continued)22.3.9 VHT preamble

Descriptions (incl mathematical) for various portions of preamble In addition, the following is notable:

• L-SIG– Value in LENGTH field determined by packet duration

• VHT-SIG-A– Detailed description of fields derived from Specification Framework– Describes rotation on second symbol as in Specification Framework

• VHT-SIG-B– Detailed description of fields derived from Specification Framework– How value in Length field is derived from LENGTH parameter in TXVECTOR– Fixed bit pattern in VHT-SIG-B for NDP in various bandwidths– Details on repetition of bits for various bandwidths (from Spec Framework)

Slide 57

ETRI

VHT PHY

22.3 VHT PLCP sub-layer (continued)22.3.11 Data field

SERVICE field• Including CRC for VHT-SIG-B• Details on CRC used (same CRC-8 used elsewhere)

Scrambler• Reference to scrambler in Clause 17 (OFDM PHY)

Coding• BCC and LDPC• Encoding process for MU packets

BCC Interleaver Constellation mapping

• Reference to Clause 17 except for 256-QAM• 256-QAM mapping defined

LDPC tone mapping

Slide 58

ETRI

VHT PHY

22.3 VHT PLCP sub-layer (continued)22.3.11.11 Non-HT duplicate transmission

Support for ‘quadruplicate’, ‘octuplicate’ non-HT transmissions (section 5 of Spec Framework)

22.3.12 Beamforming and MU-MIMO Details on V matrix feedback based beamforming and MU-MIMO

22.3.13 VHT preamble format for sounding PPDUs Sounding PPDU format (VHT PPDU without Data field)

22.3.15 Channel numbering and channelization Channels fully defined using {BW, CenterFreq, Primary20MHzChan)

22.3.20 PMD transmit specification22.3.20.1 Transmit spectral mask

From section 3.6.2 of Spec Framework

22.3.20.2 Spectral flatness From section 3.6.3 of Spec Framework

Slide 59

ETRI

VHT PHY

22.3 VHT PLCP sub-layer (continued)22.3.21 PMD receiver specification22.3.21.5 CCA sensitivity

From section 3.5 of Spec Framework Carry over 11n sensitivity requirements, extended to 80 and 160 MHz Mostly TBD for secondary channel sensitivity

22.3.22 PLCP transmit procedure Follows 11n

22.3.23 PLCP receive procedure Defer using L-SIG if error in VHT-SIG

Slide 60

ETRI

VHT PHY

22.4 VHT PLME22.4.3 TXTIME and PSDU_LENGTH calculation

Primitive by which MAC determines how much padding to add MAC passes down amount of useful data for each user PHY determines Nsym based on coding, etc. PHY determines PSDU_LENGTH (total number of octets MAC

needs to supply) for each user

Slide 61

ETRI

Annexes

Annex I Table I-2 updated for 80 MHz and 160 MHz behavior

Annex J Operating classes table updated for

• United States• Europe• Japan• Global

Following section 3.1 of Spec Framework

Slide 62

ETRIETRI 인터넷연구부문 무선통신연구부

key technology issues for ieee802.11ac next gen. wlanc1... · etri etri 인터넷연구부문...

Documents